FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Money Market Mutual Funds [Member] | Level 1 [Member]
Fair value of assets	$ 72,321	$ 527
Derivative instruments asset Forward contracts designated as hedging instruments [Member] | Level 2 [Member]
Fair value of assets	508
Derivative instruments asset Options and forward contracts not designated as hedging instruments [Member] | Level 2 [Member]
Fair value of assets	478
Short-term corporate bonds [Member] | Level 2 [Member]
Fair value of assets	113,032	91,845
Long-term corporate bonds [Member] | Level 2 [Member]
Fair value of assets	44,269	117,778
Long-term governmental bonds [Member] | Level 2 [Member]
Fair value of assets	$ 1,415	$ 1,398